Fig. 4

hTEC line, a model of aging thymic epithelium. WNT signaling pathway induction. Conventional hTEC monolayer cultures stained with anti-β-catenin monoclonal antibody (green) (a–c) and anti-human FOXN1 (red) (d–f) with DAPI nuclear counterstain: non-treated control (a, d), LiCl-treated for 6 h (b, e) and 18 h (c, f). (40x objective magnification). FOXN1 staining on a thymic human sample was used as a positive control (Fig. 4f, insert). In (g) is shown the RT-PCR detection of FOXN1 transcript after treatment with 20 mM of LiCl for 6 and 18 h. Non-treated cultures and TEC treated with 20 mM of NaCl were used as negative controls. Legend – F: FOXN1 amplification product; F (−): reverse transcriptase reaction control without enzyme from FOXN1 amplification product; H: HPRT-1 amplification product; H (−): reverse transcriptase reaction control without enzyme from HPRT-1 amplification product